This application relates generally to gas turbine engines and, more particularly, to combustors for gas turbine engine.
Air pollution concerns worldwide have led to stricter emissions standards. These standards regulate the emission of oxides of nitrogen (NOx), unburned hydrocarbons (HC), and carbon monoxide (CO) generated as a result of gas turbine engine operation. In particular, nitrogen oxide is formed within a gas turbine engine as a result of high combustor flame temperatures. Making modifications to a gas turbine engine in an effort to reduce nitrous oxide emissions often has an adverse effect on operating performance levels of the associated gas turbine engine.
In gas turbine engines, nitrous oxide emissions can be reduced by increasing airflow through the gas turbine combustor during operating conditions. Gas turbine engines include preset operating parameters and any such airflow increases are limited by the preset operating parameters including turbine nozzle cooling parameters. As a result, to increase the airflow within the gas turbine combustor, the gas turbine engine and associated components should be modified to operate at new operating parameters.
Because such gas turbine engine modifications are labor-intensive and time-consuming, users are often limited to derating the operating power capability of the gas turbine engine and prevented from operating the gas turbine engine at full capacity. Such derates do not limit an amount of nitrous oxide formed as the engine operates at full capacity, but instead limit the operating capacity of the gas turbine engine.